<?php
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=UTF-8");
header("Access-Control-Allow-Methods: POST, GET, OPTIONS, DELETE");
header("Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");

if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    http_response_code(200);
    exit();
}

// ตั้งค่าการเชื่อมต่อฐานข้อมูล MySQL
$host = "localhost";
$db_name = "it_asset";
$username = "root";
$password = "@Samui@10742";

try {
    $conn = new PDO("mysql:host=$host;dbname=$db_name;charset=utf8", $username, $password);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $exception) {
    echo json_encode(["error" => "เชื่อมต่อฐานข้อมูลไม่ได้: " . $exception->getMessage()]);
    exit;
}

$method = $_SERVER['REQUEST_METHOD'];

// ดึงข้อมูล (GET)
if ($method === 'GET') {
    try {
        $stmt = $conn->prepare("SELECT * FROM assets ORDER BY last_seen DESC");
        $stmt->execute();
        $assets = $stmt->fetchAll(PDO::FETCH_ASSOC);
        echo json_encode($assets);
    } catch (PDOException $e) {
        echo json_encode(["error" => "ดึงข้อมูลผิดพลาด: " . $e->getMessage()]);
    }
    exit;
}

// รับและอัปเดตข้อมูล (POST)
if ($method === 'POST') {
    $data = json_decode(file_get_contents("php://input"));

    if (!empty($data->hostname)) {
        // เตรียมข้อมูล
        $id              = isset($data->id) ? $data->id : null;
        $asset_tag       = !empty($data->asset_tag) ? $data->asset_tag : null;
        $hostname        = $data->hostname;
        $os_version      = isset($data->os_version) ? $data->os_version : null;
        $cpu_model       = isset($data->cpu_model) ? $data->cpu_model : null;
        $ram_gb          = isset($data->ram_gb) ? $data->ram_gb : null;
        $storage_gb      = isset($data->storage_gb) ? $data->storage_gb : null;
        $ip_address      = isset($data->ip_address) ? $data->ip_address : null;
        $mac_address     = isset($data->mac_address) ? $data->mac_address : null;
        $status          = !empty($data->status) ? $data->status : 'Active';
        $is_auto_updated = isset($data->is_auto_updated) ? $data->is_auto_updated : 1;

        try {
            if ($id) {
                // อัปเดตข้อมูลทั้งหมดผ่าน ID (แก้ไขข้อผิดพลาดแล้ว)
                $sql = "UPDATE assets SET 
                        asset_tag = :asset_tag,
                        hostname = :hostname,
                        os_version = :os_version,
                        cpu_model = :cpu_model,
                        ram_gb = :ram_gb,
                        storage_gb = :storage_gb,
                        ip_address = :ip_address,
                        mac_address = :mac_address,
                        status = :status,
                        is_auto_updated = :is_auto_updated,
                        last_seen = NOW()
                        WHERE id = :id";

                $stmt = $conn->prepare($sql);
                $stmt->execute([
                    ':asset_tag' => $asset_tag,
                    ':hostname' => $hostname,
                    ':os_version' => $os_version,
                    ':cpu_model' => $cpu_model,
                    ':ram_gb' => $ram_gb,
                    ':storage_gb' => $storage_gb,
                    ':ip_address' => $ip_address,
                    ':mac_address' => $mac_address,
                    ':status' => $status,
                    ':is_auto_updated' => $is_auto_updated,
                    ':id' => $id
                ]);
            } else {
                // ตรวจสอบเครื่องที่มีอยู่แล้ว (กรณี Agent/เพิ่มใหม่)
                $check = $conn->prepare("SELECT id FROM assets WHERE hostname = :hostname LIMIT 1");
                $check->execute([':hostname' => $hostname]);
                $exists = $check->fetch(PDO::FETCH_ASSOC);

                if ($exists) {
                    $sql = "UPDATE assets SET 
                            asset_tag = COALESCE(:asset_tag, asset_tag),
                            os_version = COALESCE(:os_version, os_version),
                            cpu_model = COALESCE(:cpu_model, cpu_model),
                            ram_gb = COALESCE(:ram_gb, ram_gb),
                            storage_gb = COALESCE(:storage_gb, storage_gb),
                            ip_address = COALESCE(:ip_address, ip_address),
                            mac_address = COALESCE(:mac_address, mac_address),
                            status = COALESCE(:status, status),
                            is_auto_updated = :is_auto_updated,
                            last_seen = NOW()
                            WHERE id = :id";

                    $stmt = $conn->prepare($sql);
                    $stmt->execute([
                        ':asset_tag' => $asset_tag,
                        ':os_version' => $os_version,
                        ':cpu_model' => $cpu_model,
                        ':ram_gb' => $ram_gb,
                        ':storage_gb' => $storage_gb,
                        ':ip_address' => $ip_address,
                        ':mac_address' => $mac_address,
                        ':status' => $status,
                        ':is_auto_updated' => $is_auto_updated,
                        ':id' => $exists['id']
                    ]);
                } else {
                    $sql = "INSERT INTO assets (asset_tag, hostname, os_version, cpu_model, ram_gb, storage_gb, ip_address, mac_address, status, is_auto_updated) 
                            VALUES (:asset_tag, :hostname, :os_version, :cpu_model, :ram_gb, :storage_gb, :ip_address, :mac_address, :status, :is_auto_updated)";

                    $stmt = $conn->prepare($sql);
                    $stmt->execute([
                        ':asset_tag' => $asset_tag,
                        ':hostname' => $hostname,
                        ':os_version' => $os_version,
                        ':cpu_model' => $cpu_model,
                        ':ram_gb' => $ram_gb,
                        ':storage_gb' => $storage_gb,
                        ':ip_address' => $ip_address,
                        ':mac_address' => $mac_address,
                        ':status' => $status,
                        ':is_auto_updated' => $is_auto_updated
                    ]);
                }
            }

            echo json_encode(["success" => true, "message" => "บันทึกข้อมูลสำเร็จ"]);
        } catch (PDOException $e) {
            if ($e->getCode() == 23000) {
                echo json_encode(["error" => "รหัสทรัพย์สิน (Asset Tag) หรือ MAC Address นี้ถูกใช้ในระบบไปแล้ว"]);
            } else {
                echo json_encode(["error" => "เกิดข้อผิดพลาดที่ฐานข้อมูล: " . $e->getMessage()]);
            }
        }
    } else {
        echo json_encode(["error" => "ข้อมูลไม่ครบถ้วน กรุณาระบุชื่อเครื่อง"]);
    }
}